Plants 1-2 cm, in erect, basal tufts or cushions, green or brownish green. Stems yellow or brownish green; cross section irregularly pentagonal, cortical cells in 2-4 layers, medulla cell walls thick or thin, central strand cells small; rhizoids between leaves near base of plants. Leaves distant near base of plants, more congested toward apex, not much different when dry or moist, oblong-lanceolate, widest above base, somewhat concave to keeled; base slightly rounded to insertion; margins revolute to mid leaf, weakly serrulate proximally, irregularly serrulate toward apex; apex acute; costa flexuose; laminal cells round or nearly oblong, papillae blunt; basal cells 1-stratose, hyaline. Specialized asexual reproduction by small fusiform propagula in tight globose cluster. Perigonia budlike in series down stem; paraphyses of 7-10 cells. Perichaetia with paraphyses of 9-12 cells. Seta 1-1.5 cm. Capsule suberect or horizontal, 2.5-3 mm; operculum conic, rostrum short, blunt; endostome cilia nodose. Spores 10-20 µm, smooth.
1. Aulacomnium androgynum (Hedw.) Schwaegr. 沼泽皱蒴藓 zhao ze zhou shuo xian Sp. Musc. Frond., Suppl. 3, 1: 215. 1827. Fusiconia androgyna (Hedw.) P. de Beauv. ex Brid., Bryol. Univ. 2: 5. 1827, nom. illeg. Gymnocybe androgyna (Hedw.) Fries., Stirp. Agri Femsion. 27. 1825. Orthopyxis androgyna (Hedw.) P. de Beauv., Prodr. Aethéogam. 79. 1805. Mnium androgynum (Hedw.) Smith, Trans. Linn. Soc. London 7: 261. 1804. Bryum androgynum Hedw., Sp. Musc. Frond. 178. 1801. Type: Europe. Plants small to medium-sized, green to yellowish green, in dense tufts. Stems erect, up to 2.5 cm high, branched, with rhizoids at base. Leaves not or somewhat decurrent at base, lower ones oblong-lanceolate to lanceolate; upper leaves linear-lanceolate; margins irregularly denticulate, involute; costae percurrent or ending below the apex, somewhat flexuous; leaf cells nearly uniform, small, rounded-hexagonal, thick-walled, unipapillose, strongly thickened at corners, resulting in stellate appearance; basal cells at the insertion not inflated, rounded-hexagonal, unistratose, with large papillae. Gemmae short-stalked. Dioicous. Setae 1.0–2.0 cm long; capsules erect when dry, inclined when mature, cylindrical, slightly curved, reddish brown; opercula shortly rostrate.